The invention relates to a dynamometer for a sucker rod pump comprising a pendulum potentiometer and a load sensor.
Known prior art methods of reading the forces on a sucker rod pump used in lifting oil from oil wells employ a load cell and a chart which is rotated on a drum by a cable. Such methods produce a diagram which may be analyzed for determining the minimum force on the pump, the maximum force on the pump, the area of the force-versus-stroke curve, and the shape of the force-versus-stroke curve. The area of the force-versus-stroke curve itself is usually measured by means of a polar planimeter. By minimizing the area of the force-versus-stroke curve, the efficiency of the pump can be maximized. Operating characteristics of the pump can be changed by adjusting the position of a counterweight mounted on an arm which is driven by the pump motor. The shape of the force-versus-stroke curve itself is an indication of conditions within the borehole. Prior methods of analyzing this curve do not give exact results and are time consuming.